Linked Life Data

7789417

Source:http://linkedlifedata.com/resource/pubmed/id/7789417

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1995-7-27
pubmed:abstractText
A new apparatus has been developed using the laser speckle phenomenon for non-contact, two-dimensional analysis of tissue circulation in the choroid and optic nerve head (ONH). The fundus was illuminated by a diode laser spot and its image speckle was detected by an image sensor. The difference between the average of the speckle intensity (Imean) and the speckle intensity for successive scannings was calculated, and the ratio of Imean to this difference was defined as normalized blur (NB), which is a quantitative index of blood velocity. The results were displayed on color graphic monitors showing the two-dimensional variation of the NB level in the measurement field. In the rabbit, this apparatus was used to study the relationship between the results of NB measurement and the choroidal blood flow determined by the microsphere technique, the relationship between NB obtained from the ONH tissue free of visible surface vessels and the ocular perfusion pressure (OPP) after a lethal injection of pentobarital, and the effect of intraocular pressure (IOP) on the NB in the choroid or in the ONH. A stepwise reduction in the OPP was introduced by elevating the IOP manometrically. The relative decrease in the average NB over the field measured, NBav, in the choroid with the reduction in OPP showed a significant correlation with the relative change in the blood flow rate determined using the microsphere technique (r = 0.60, P < 0.001). NBav in the ONH had a good correlation with the OPP after a lethal injection of pentobarbital (r = 0.98, P < 0.001). NBav in the choroid decreased with reduction in the OPP. Although NBav in the ONH was little affected by OPP change when OPP was above 40 mmHg, at OPP levels below 40 mmHg, NBav in the ONH decreased along with a reduction in the OPP. These results suggest that by using the present apparatus, the blood velocity in the choroid or ONH under various conditions can be studied non-invasively in the living eye.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0014-4835
pubmed:author
pubmed:issnType
Print
pubmed:volume
60
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
373-83
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Non-contact, two-dimensional measurement of tissue circulation in choroid and optic nerve head using laser speckle phenomenon.
pubmed:affiliation
Eye Clinic, Tokyo Metropolitan Geriatric Hospital, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't